Wang Ting-Ting, Shi Zhi Qi, Hu Liang-Bin, Xu Xiao-Feng, Han Fengxiang X, Zhou Li-Gang, Chen Jian
Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences , Nanjing 210014, China.
College of Life Sciences, Nanjing Normal University , Nanjing 210064, China.
J Agric Food Chem. 2017 Aug 30;65(34):7396-7405. doi: 10.1021/acs.jafc.7b02950. Epub 2017 Aug 17.
Thymol has been developed as medicine and food preservative due to its immune-regulatory effect and antimicrobial activity, respectively. However, little is currently known about the role of thymol in the modulation of plant physiology. In the present study, we applied biochemical and histochemical approaches to investigate thymol-induced tolerance in rice (Oryza sativa) seedlings against Cd (cadmium) stress. Thymol at 20 μM recovered root growth completely upon CdCl exposure. Thymol pronouncedly decreased Cd-induced ROS accumulation, oxidative injury, cell death, and Cd accumulation in roots. Pharmaceutical experiments suggested that endogenous NO mediated Cd-induced phytotoxicity. Thymol decreased Cd-induced NO accumulation by suppressing the activity of NOS (nitric oxide synthase) and NR (nitrate reductase) in root. The application of NO donor (SNP, sodium nitroprusside) resulted in the increase in endogenous NO level, which in turn compromised the alleviating effects of thymol on Cd toxicity. Such findings may helpful to illustrate the novel role of thymol in the modulation of plant physiology, which may be applicable to improve crop stress tolerance.
百里香酚因其免疫调节作用和抗菌活性，分别被开发用作药物和食品防腐剂。然而，目前对于百里香酚在调节植物生理方面的作用知之甚少。在本研究中，我们应用生化和组织化学方法，研究百里香酚诱导水稻幼苗对镉胁迫的耐受性。20 μM的百里香酚在暴露于CdCl后能完全恢复根系生长。百里香酚显著降低了镉诱导的活性氧积累、氧化损伤、细胞死亡以及根系中的镉积累。药理学实验表明，内源性一氧化氮介导了镉诱导的植物毒性。百里香酚通过抑制根系中一氧化氮合酶（NOS）和硝酸还原酶（NR）的活性，降低了镉诱导的一氧化氮积累。施用一氧化氮供体（SNP，硝普钠）导致内源性一氧化氮水平升高，进而削弱了百里香酚对镉毒性的缓解作用。这些发现可能有助于阐明百里香酚在调节植物生理方面的新作用，这可能适用于提高作物的胁迫耐受性。
